Differential pulse code modulation (DPCM) converts an analog signal into a digital signal. Specifically, the analog signal is sampled, and a difference between the actual sampled value and its predicted sample is quantized and then encoded to create a digital value. The predicted sample of the sampled value may be determined based on previous samples of the analog signal. Alternatively, instead of utilizing a predicted sample, the difference may be determined based on the actual sampled value and a previously sampled value. The analog signal may be, for example, data recorded by a sensor. Specifically, data may be collected from various sensors in a system by translating physical data, such as temperature or pressure, into electrical analog signals that represent the physical data.
DPCM is a relatively efficient approach for transmitting data in terms of bandwidth utilization, as only the quantized differences in signal values are encoded and transmitted. DPCM compares two successive analog amplitude values, quantizes and encodes the difference between the analog amplitude values, and transmits the differential value. As it can be assumed that the change, or differential, in the analog signal (i.e., the change in temperature or pressure monitored by the sensor) occurs relatively gradually, sometimes only a few bits may be required to represent each sample. DPCM will work with various numbers of bits such as, for example, a 4-bit approach, an 8-bit approach, or even a 10-bit approach.